1-1 Scope.
This standard contains minimum requirements for the design, installation, and maintenance of foam-water sprinkler and spray systems. These systems shall be designed with the required density for either foam or water application as the controlling factor, depending on the design purpose of the system. It is not the intent of this standard to specify where foam-water sprinkler and spray protection is required. The determination of where foam-water sprinklers and spray systems are required shall be made in accordance with such applicable standards as NFPA 30, Flammable and Combustible Liquids Code, and NFPA 409, Standard on Aircraft Hangars.

The purpose of this standard is to provide a reasonable degree of protection for life and property from fire through installation requirements for foam-water sprinkler and spray systems based on sound engineering principles, test data, and field experience.
Nothing in this standard is intended to restrict new technologies or alternate arrangements, provided the level of safety prescribed by the standard is not lowered.

Unless otherwise noted, the provisions of this document are not intended to be applied to facilities, equipment, structures, or installations that were existing or approved for construction or installation prior to the effective date of the document, except in those cases where it is determined by the authority having jurisdiction that the existing situation involves a distinct hazard to life or adjacent property.

Foam.* Within the scope of this standard, a stable aggregation of small bubbles of lower density than oil or water that exhibits a tenacity for covering horizontal surfaces. Air foam is made by mixing air into a water solution containing a foam concentrate by means of suitably designed equipment. It flows freely over a burning liquid surface and forms a tough, air-excluding, continuous blanket that seals volatile combustible vapors from access to air. It resists disruption from wind and draft or heat and flame attack, and is capable of resealing in case of mechanical rupture. Fire-fighting foams retain these properties for relatively long periods of time. Foams also are defined by expansion and are arbitrarily subdivided into three ranges of expansion. These ranges correspond broadly to certain types of usage described below.

Foam Concentrates. A concentrated liquid foaming agent as received from the manufacturer. For the purpose of this document, “foam concentrate” and “concentrate” are used interchangeably.

Protein-Foam Concentrates. Protein-foam concentrates consist primarily of products from a protein hydrolysate, plus stabilizing additives and inhibitors to protect against freezing, to prevent corrosion of equipment and containers, to resist bacterial decomposition, to control viscosity, and to otherwise ensure readiness for use under emergency conditions. They are diluted with water to form 3 percent to 6 percent solutions depending on the type. These concentrates are compatible with certain dry chemicals.

Began involving in translation of technical documents in 1986 when working in a research institute; from mid-90s, living on translation jobs.

Alos translated a lot of articles in other fields such as business affairs, marketing, contracts, bidding documents, etc. but far less than engineering ones

Also do translation from Chinese to English for domestic clients. Of couse, that is, im some way, a kind of technically correct but Chinese-type English as what we chinese call it - "Chinglish". But I will make my life-long endeavour to write well in native English